University of Pembangunan Nasional Veteran, Yogyakarta
Yogyakarta, Indonesia
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Suharsono,University of Pembangunan Nasional Veteran, Yogyakarta | Nurdian S.W.,University of Pembangunan Nasional Veteran, Yogyakarta | Palupi I.R.,University of Pembangunan Nasional Veteran, Yogyakarta
Journal of Physics: Conference Series | Year: 2016

Relocating hypocenter is a way to improve the velocity model of the subsurface. One of the method is Grid Search. To perform the distribution of the velocity in subsurface by tomography method, it is used the result of relocating hypocenter to be a reference for subsurface analysis in volcanic and major structural patterns, such as in Central Java. The main data of this study is the earthquake data recorded from 1952 to 2012 with the P wave number is 9162, the number of events is 2426 were recorded by 30 stations located in the vicinity of Central Java. Grid search method has some advantages they are: it can relocate the hypocenter more accurate because this method is dividing space lattice model into blocks, and each grid block can only be occupied by one point hypocenter. Tomography technique is done by travel time data that has had relocated with inversion pseudo bending method. Grid search relocated method show that the hypocenter's depth is shallower than before and the direction is to the south, the hypocenter distribution is modeled into the subduction zone between the continent of Eurasia with the Indo-Australian with an average angle of 14. The tomography results show the low velocity value is contained under volcanoes with value of -8% to -10%, then the pattern of the main fault structure in Central Java can be description by the results of tomography at high velocity that is from 8% to 10% with the direction is northwest and northeast-southwest. © Published under licence by IOP Publishing Ltd.

Elistyawati Y.,University of Pembangunan Nasional Veteran, Yogyakarta | Palupi I.R.,University of Pembangunan Nasional Veteran, Yogyakarta | Suharsono,University of Pembangunan Nasional Veteran, Yogyakarta
Journal of Physics: Conference Series | Year: 2016

In this study the tectonic earthquakes was observed through the peak ground acceleration through the PSHA method by dividing the area of the earthquake source. This study applied the earthquake data from 1965 - 2015 that has been analyzed the completeness of the data, location research was the entire Java with stressed in four large cities prone to earthquakes. The results were found to be a hazard map with a return period of 500 years, 2500 years return period, and the hazard curve were four major cities (Jakarta, Bandung, Yogyakarta, and the city of Banyuwangi). Results Java PGA hazard map 500 years had a peak ground acceleration within 0 g ≥ 0.5 g, while the return period of 2500 years had a value of 0 to ≥ 0.8 g. While, the PGA hazard curves on the city's most influential source of the earthquake was from sources such as fault Cimandiri backgroud, for the city of Bandung earthquake sources that influence the seismic source fault dent background form. In other side, the city of Yogyakarta earthquake hazard curve of the most influential was the source of the earthquake background of the Opak fault, and the most influential hazard curve of Banyuwangi earthquake was the source of Java and Sumba megatruts earthquake. © Published under licence by IOP Publishing Ltd.

Yahya A.,University of Pembangunan Nasional Veteran, Yogyakarta | Palupi M.I.R.,University of Pembangunan Nasional Veteran, Yogyakarta | Suharsono,University of Pembangunan Nasional Veteran, Yogyakarta
Journal of Physics: Conference Series | Year: 2016

Sumatra region is one of the earthquake-prone areas in Indonesia because it is lie on an active tectonic zone. In 2004 there is earthquake with a moment magnitude of 9.2 located on the coast with the distance 160 km in the west of Nanggroe Aceh Darussalam and triggering a tsunami. These events take a lot of casualties and material losses, especially in the Province of Nanggroe Aceh Darussalam and North Sumatra. To minimize the impact of the earthquake disaster, a fundamental assessment of the earthquake hazard in the region is needed. Stages of research include the study of literature, collection and processing of seismic data, seismic source characterization and analysis of earthquake hazard by probabilistic methods (PSHA) used earthquake catalog from 1907 through 2014. The earthquake hazard represented by the value of Peak Ground Acceleration (PGA) and Spectral Acceleration (SA) in the period of 0.2 and 1 second on bedrock that is presented in the form of a map with a return period of 2475 years and the earthquake hazard curves for the city of Medan and Banda Aceh. © Published under licence by IOP Publishing Ltd.

Adu N.,University of Pembangunan Nasional Veteran, Yogyakarta | Indriati Retno P.,University of Pembangunan Nasional Veteran, Yogyakarta | Suharsono,University of Pembangunan Nasional Veteran, Yogyakarta
AIP Conference Proceedings | Year: 2016

Monitoring of micro seismic activity in the geothermal field is useful to know the fracture controllers in the geothermal reservoir area. However, in determining the point of micro earthquake, hypocenters still contain inherent uncertainties due to several factors such as mismatches velocity model used by the actual subsurface conditions. For that reason, hypocenter relocation by Markov Chain method is used, to simulate the hypocenter point spatially based opportunities transition containing the principle of conditional probability. The purpose of this relocation is to improve the models of the hypocenter so that the interpretation of the subsurface structure is better. From the result of the relocation of using Markov Chain identified fault structures trending below the surface of the northeast-southwest (NE-SW) with approximately N38°E. This structure is suspected as the continuity of the structure in the surface. The depth of the hypocenter is located 758?m above mean sea level more than 800?m below mean sea level. © 2016 AIP Publishing LLC.

Nurcholis M.,University of Pembangunan Nasional Veteran, Yogyakarta | Mulyanto D.,University of Pembangunan Nasional Veteran, Yogyakarta
International Journal of Applied Engineering Research | Year: 2017

South beach of Kulon Progo Regency, Yogyakarta is a boundary on the south side bordered by the Indian Ocean. The sand material of this beach is containing a high value of metal minerals, so that it has a potential to be exploited. Local communities had been managing the land with continuous effort to convert the sandy soil that was extremely low nutrient availability to be the productive farming land. The aimed of the study was to examine the characteristics of minerals and chemistry of the residue produced as a fine-sized material, light metal and also the mineral which may degrades the land and air quality. Analysis of fertility from the residue consist of pH, cation exchange capacity (CEC), and the bases (Ca2+, Mg2+, K+, Na+) were extracted using NH4OAc. Elements analysis of materials was done by neutron activation analysis (NAA). The results of the present study showed that: 1) An increasing of concentration of heavy metal elements namely Ce and Cr on the residue. 2) There were iron minerals (ilmenite, magnetite), silica (crystobalite) and vanadinite potentially degrade the quality of air and soil environment. 3) The processing of iron-sand increase the concentration of minerals as a source of nutrients, namely: feldspar, olivine, augite and amphibole. 4) The residue produced from iron-sand processing can provide the elements of Ca, Mg, K, Na and P required by plants. © Research India Publications.

Suranto A.M.,University of Pembangunan Nasional Veteran, Yogyakarta | Heru P.S.,University of Pembangunan Nasional Veteran, Yogyakarta
Energy Procedia | Year: 2017

Steam assisted gravity drainage (SAGD) method for heavy oil exploitation using horizontal wells has been done and successful in the field. In the similar concept with SAGD using horizontal wells, vertical well SAGD has been developed as alternative method. This well consists of two strings where one is as a producer on the bottom and the other one is as an injector on the top. This investigation makes different distance between injector and producer perforations gradually. The aim of this research is to make optimization strategy on the vertical well SAGD. The sensitivities tested consist of injection rate and distance between producer and injector perforations. Analysis result reveals that the impact of multilevel injector will decrease cSOR and improve the production rate on the same injection rate. If the process is combined with multilevel injection rate, the result would offer the most favourable option. Furthermore, the longer distance between producer and injector perforations will cause longer restrained heat in reservoir so that the volume steam chamber will be bigger and drainage radius will be wider. © 2017 The Authors.

Muttaqin Z.,University of Pembangunan Nasional Veteran, Yogyakarta
IET Conference Publications | Year: 2015

A quick, reliable reservoir characterization using core data must provide both geological and engineering works. The new proposed method of pore geometry-structure relating the hydraulic characterization of pore system can lead to improved reservoir characterization. This study is facilitated with 126 core samples of Well-A. PGS method is based on capillary model equation involving hydraulic parameter: effective hydraulic diameter and mean as geometry parameter and hydraulic conductivity as structure parameter. Plot of (k/ø)0.5 vs k/ø3 based on lithofacies description, each rock type will have distinct line whose slopes no more than 0.5 Then porosity-saturation-permeability correlations are formed to result equation predicting permeability from Well-A calibrated by SCAL data. It's demonstrated that cross-plot of the effective hydraulic diameter against porosity can be used to predict permeability. Permeability data distribution method as a comparison and PGS method were simulated in single Well model. It results 9 rock types which 5 of them have been validated with J-Function curve; the permeability prediction in which PGS method shows high accuracy (R2 = 0.9951); after simulated, PGS contributes RF 13.43% or is higher 5.46% against permeability data distribution method. It could be alternative reservoir characterization when using reliable core data that is beneficial in petroleum industry.

Setyoningrum T.M.,University of Pembangunan Nasional Veteran, Yogyakarta | Nur M.M.A.,University of Pembangunan Nasional Veteran, Yogyakarta
Biocatalysis and Agricultural Biotechnology | Year: 2015

Production of phycocyanin from Spirulina platensis by mixotrophic condition was favored due to high growth rate result. The objective of this research was to obtain the statistical interaction models of molasses and urea to crude phycocyanin (CPC) production by applying response surface methology (RSM)associated central composite design approach. S. platensis was cultivated under mixotrophic condition by adding varied molasses and urea under continous illumination at 45.5μmolm-2 s-1 for 6 days. By using 2nd order statistical models, optimum phycocyanin production was recorded on 114.74mgL-1 and 0.196L-1 of urea and molasses, respectively. Molasses could be the promising substrate for phycocyanin production of the microalgae. © 2015 Elsevier Ltd.

Muafi,University of Pembangunan Nasional Veteran, Yogyakarta
Journal of Industrial Engineering and Management | Year: 2015

Purpose: This study aims at analyzing the role of empowerment of Green Information Technology (IT) in Small Medium Entreprises (SMEs) and social capital of the creativity and innovation of creative SMEs in Bantul, Yogyakarta, Indonesia. Design/methodology/approach: A statistical technique used in the present study was Partial Least Square. The primary data of the present research were obtained from questionnaires and interviews with some respondents. While secondary data were gained through the records and publications of related instances. Findings: The research concluded that the empowerment of Green IT provides a significant role in creativity and innovation as well as social capital, and at the same time it also supplies a significant role in innovation. Research limitations/implications:. This study is proposed to fill the research gap and at the same time to emphasize the importance of the creative empowerment of SMEs in Indonesia in adopting Green IT and that they are not only ready to make use of Green IT. Green IT empowerment and social capital in the creative SMEs play an important function ingenerating of creativity and innovation in the Yogyakarta’s creative SMEs. Creative industries which capitalize creative ideas and skills are expected to positively contribute to support the national economy. Practical implications: Creative SMEs grow and develop rapidly here and form clusters of creative industries in accordance with the resources of each cluster. Originality/value: This paper is a first attempt to overlook the significant role of green IT empowerment in SMEs’ rapid development in Yogyakarta, a growing province in economic sector in Indonesia. The result of the study is expected to lead other similar research which in the future will craft out the role of economic development and the use of environmental friendly material of production. © 2015, Universitat Politecnica de Catalunya. All rights reserved.

Indrianti N.,University of Pembangunan Nasional Veteran, Yogyakarta | Biru N.B.,University of Pembangunan Nasional Veteran, Yogyakarta | Wibawa T.,University of Pembangunan Nasional Veteran, Yogyakarta
Procedia CIRP | Year: 2016

This study deals with noise problem at the Indonesian teak wood furniture manufacturing company called PT Jawa Furni Lestari. The noise is generated by air compressor which is used for dyeing and spraying processes in the assembly area. The highest noise intensity indicates the value of 106.28 dB, which passes the threshold value i.e. 85 dB. The aim of this study is to reduce the noise level by constructing noise barrier. We used Pahl and Beitz approach for the barrier development process and modified idle space under the stairs in the assembly area. Consequently the compressor must be relocated from its present location. The result of the study shows that the construction of the barrier could reduce noise by 32.29 dB. In addition to reducing noise due to barrier construction, compressor relocation provides larger area for production activities. The evaluation result shows that the operators in the assembly area are very satisfied with the condition after the barrier is constructed. © 2016 The Authors. Published by Elsevier B.V.

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